MCQ Quiz: Direct Oral Anticoagulants

Direct Oral Anticoagulants (DOACs) have revolutionized the management of thromboembolic disorders, offering alternatives to warfarin with more predictable pharmacokinetics and fewer monitoring requirements. For PharmD students, a deep understanding of these agents—including their mechanisms, indications, specific dosing considerations, and reversal strategies—is essential for ensuring safe and effective patient care in a rapidly evolving therapeutic landscape.

1. Dabigatran exerts its anticoagulant effect by directly inhibiting which of the following clotting factors?

  • Factor Xa
  • Thrombin (Factor IIa)
  • Vitamin K epoxide reductase
  • Platelet aggregation


Answer: Thrombin (Factor IIa)


2. Rivaroxaban, apixaban, and edoxaban are all members of which class of anticoagulants?

  • Vitamin K antagonists
  • Direct Thrombin Inhibitors
  • Direct Factor Xa Inhibitors
  • Low-Molecular-Weight Heparins


Answer: Direct Factor Xa Inhibitors


3. A major advantage of DOACs compared to warfarin is:

  • The need for frequent routine laboratory monitoring
  • Their long half-life, making missed doses less critical
  • Their rapid onset of action and fewer drug-food interactions
  • The availability of a single, universal reversal agent


Answer: Their rapid onset of action and fewer drug-food interactions


4. The approved reversal agent for dabigatran is:

  • Protamine sulfate
  • Vitamin K
  • Idarucizumab
  • Andexanet alfa


Answer: Idarucizumab


5. Andexanet alfa is a reversal agent specifically designed for which class of medications?

  • Direct Thrombin Inhibitors
  • Warfarin
  • Factor Xa Inhibitors
  • Unfractionated heparin


Answer: Factor Xa Inhibitors


6. Which DOAC should be taken with food to ensure adequate absorption?

  • Apixaban
  • Dabigatran
  • Rivaroxaban (for doses of 15 mg and 20 mg)
  • Edoxaban


Answer: Rivaroxaban (for doses of 15 mg and 20 mg)


7. DOACs are commonly used for stroke prevention in which of the following conditions?

  • Peripheral artery disease
  • Non-valvular atrial fibrillation
  • Stable angina
  • Essential hypertension


Answer: Non-valvular atrial fibrillation


8. When initiating treatment for an acute venous thromboembolism (VTE), which DOAC requires an initial period of parenteral anticoagulation before it can be started?

  • Rivaroxaban
  • Apixaban
  • Edoxaban
  • Dabigatran


Answer: Edoxaban


9. Dosing adjustments for most DOACs are primarily based on which patient parameter?

  • Liver function
  • Body mass index (BMI)
  • Renal function (creatinine clearance)
  • Blood pressure


Answer: Renal function (creatinine clearance)


10. Strong inhibitors of both P-glycoprotein (P-gp) and CYP3A4 can have what effect on the concentration of rivaroxaban or apixaban?

  • Decrease their concentration
  • Increase their concentration, raising the risk of bleeding
  • No effect on their concentration
  • Convert them to their active metabolites more quickly


Answer: Increase their concentration, raising the risk of bleeding


11. Unlike warfarin, routine monitoring of the anticoagulant effect of DOACs is generally:

  • Required on a weekly basis
  • Performed using the INR
  • Not necessary due to their predictable pharmacokinetics
  • Done by measuring platelet count


Answer: Not necessary due to their predictable pharmacokinetics


12. A key counseling point for a patient starting a DOAC is the importance of:

  • Maintaining a consistent intake of Vitamin K
  • Adherence, as a missed dose can quickly lead to loss of anticoagulant effect due to a short half-life
  • Getting their INR checked every week
  • Taking the medication only when they feel symptoms


Answer: Adherence, as a missed dose can quickly lead to loss of anticoagulant effect due to a short half-life


13. A patient is being transitioned from warfarin to a DOAC. The DOAC can typically be started when the patient’s INR is:

  • Above 3.0
  • Between 2.5 and 3.0
  • Below 2.0 (or as specified by the manufacturer)
  • The INR value does not matter for the transition


Answer: Below 2.0 (or as specified by the manufacturer)


14. A DOAC may be preferred over warfarin in a patient who:

  • Has a stable TTR of 90%
  • Has a mechanical heart valve
  • Has difficulty with frequent INR monitoring or has an unstable INR
  • Is taking strong P-gp and CYP3A4 inducers like rifampin


Answer: Has difficulty with frequent INR monitoring or has an unstable INR


15. One of the “expanded DOAC indications” includes use in combination with aspirin for certain patients with:

  • A recent stroke
  • Coronary Artery Disease (CAD) or Peripheral Artery Disease (PAD)
  • A new diagnosis of hypertension
  • A recent DVT


Answer: Coronary Artery Disease (CAD) or Peripheral Artery Disease (PAD)


16. For the treatment of VTE, both apixaban and rivaroxaban have an initial phase of:

  • Parenteral bridge therapy
  • Higher, more frequent dosing for the first 7-21 days
  • Once-daily low-dose therapy
  • INR monitoring


Answer: Higher, more frequent dosing for the first 7-21 days


17. What is a significant disadvantage of DOACs compared to warfarin?

  • Slower onset of action
  • Higher number of food interactions
  • Higher drug acquisition cost and the need for renal dose adjustments
  • The need for routine monitoring


Answer: Higher drug acquisition cost and the need for renal dose adjustments


18. The overview of DOAC therapy for a student pharmacist would include their mechanisms, indications, and:

  • Reversal strategies
  • Marketing budgets
  • Manufacturing processes
  • Chemical synthesis pathways


Answer: Reversal strategies


19. Which of the following is a direct thrombin inhibitor?

  • Apixaban
  • Rivaroxaban
  • Edoxaban
  • Dabigatran


Answer: Dabigatran


20. When managing a patient with a DOAC-related bleed, the first step is always to:

  • Administer the reversal agent
  • Discontinue the anticoagulant and provide supportive care
  • Start a heparin infusion
  • Check an INR


Answer: Discontinue the anticoagulant and provide supportive care


21. A patient on apixaban for atrial fibrillation is scheduled for a major surgery. The apixaban should be held for at least ________ before the procedure.

  • 12 hours
  • 24 hours
  • 48 hours
  • 72 hours


Answer: 48 hours


22. Which of the following drugs is a strong P-gp and CYP3A4 inducer that can significantly decrease DOAC levels?

  • Amiodarone
  • Ketoconazole
  • Rifampin
  • Diltiazem


Answer: Rifampin


23. The use of DOACs is generally not recommended in which patient population?

  • Patients with non-valvular atrial fibrillation
  • Patients with mechanical heart valves
  • Patients undergoing knee replacement surgery
  • Patients with a deep vein thrombosis


Answer: Patients with mechanical heart valves


24. A pharmacist’s role in DOAC therapy includes counseling on the risk of:

  • Thrombosis
  • Bleeding
  • Adherence
  • All of the above


Answer: All of the above


25. A review of DOAC literature for atrial fibrillation would compare the efficacy and safety of DOACs against which traditional therapy?

  • Aspirin
  • Clopidogrel
  • Warfarin
  • Heparin


Answer: Warfarin


26. Dabigatran is formulated as a prodrug and is available in a capsule that should not be:

  • Taken with food
  • Stored in its original container
  • Crushed, chewed, or opened
  • Taken by patients with a history of VTE


Answer: Crushed, chewed, or opened


27. A specific laboratory test that can be used to estimate the effect of a Factor Xa inhibitor is a(n):

  • aPTT
  • INR
  • Anti-Xa level
  • Platelet count


Answer: Anti-Xa level


28. An “overview of DOAC therapy” for a practitioner would emphasize their role as an alternative to:

  • Warfarin
  • Statins
  • Beta-blockers
  • ACE inhibitors


Answer: Warfarin


29. For VTE treatment and prevention of recurrence, DOACs are often preferred due to:

  • Their complicated dosing regimens
  • The need for frequent blood draws
  • Their efficacy and improved safety profile regarding intracranial hemorrhage compared to warfarin
  • Their low cost


Answer: Their efficacy and improved safety profile regarding intracranial hemorrhage compared to warfarin


30. Which of these DOACs directly binds to the active site of Factor Xa?

  • Dabigatran
  • Warfarin
  • Apixaban
  • Heparin


Answer: Apixaban


31. The choice of which DOAC to use in a patient may depend on:

  • Renal function
  • The specific indication
  • Potential drug interactions
  • All of the above


Answer: All of the above


32. The “peri-procedural anticoagulation management” of DOACs is generally simpler than warfarin because:

  • DOACs have a much shorter half-life
  • DOACs do not need to be stopped before surgery
  • Warfarin has a rapid offset of action
  • DOACs do not increase bleeding risk


Answer: DOACs have a much shorter half-life


33. Apixaban has been studied and shown to be an effective option for the treatment of VTE associated with which condition?

  • Hypertension
  • Diabetes
  • Cancer
  • Asthma


Answer: Cancer


34. A patient misses a dose of their twice-daily apixaban. What is the correct advice?

  • Skip the dose and wait for the next scheduled dose
  • Take the missed dose as soon as they remember, and then continue with the regular schedule
  • Double the next scheduled dose
  • Stop taking the medication permanently


Answer: Take the missed dose as soon as they remember, and then continue with the regular schedule


35. A key learning objective for a student pharmacist regarding DOACs is to understand their use in:

  • Atrial fibrillation and VTE treatment
  • Only rare, orphan diseases
  • Non-prescription settings
  • Compounding sterile preparations


Answer: Atrial fibrillation and VTE treatment


36. Unlike warfarin, the anticoagulant effect of DOACs is less affected by:

  • Renal function
  • Dietary intake of Vitamin K
  • CYP2C9 inducers
  • Age


Answer: Dietary intake of Vitamin K


37. Before prescribing a DOAC, it is essential to obtain a baseline:

  • INR
  • Liver function panel
  • Renal function assessment (e.g., serum creatinine)
  • Lipid panel


Answer: Renal function assessment (e.g., serum creatinine)


38. The selection of a reversal agent for a DOAC depends on:

  • Which specific DOAC the patient is taking
  • The patient’s age
  • The patient’s insurance plan
  • The time of day


Answer: Which specific DOAC the patient is taking


39. A DOAC PowerPoint assignment for students would likely involve a deep dive into:

  • A specific clinical question or comparison of DOACs based on literature
  • The history of warfarin
  • The manufacturing process of DOACs
  • The marketing strategies for a new DOAC


Answer: A specific clinical question or comparison of DOACs based on literature


40. A pharmacist receives a prescription for dabigatran for a patient with a CrCl of 25 mL/min. The pharmacist should:

  • Dispense the prescription as written
  • Question the appropriateness of the dose or drug due to severe renal impairment
  • Recommend switching to warfarin without consulting the prescriber
  • Tell the patient the drug is not effective


Answer: Question the appropriateness of the dose or drug due to severe renal impairment


41. The term “direct” in Direct Oral Anticoagulants refers to their action of:

  • Binding directly to their target clotting factor
  • Being prescribed directly by a pharmacist
  • Being available for direct-to-consumer purchase
  • Having a direct effect on blood pressure


Answer: Binding directly to their target clotting factor


42. Which of the following is NOT a DOAC?

  • Apixaban
  • Warfarin
  • Rivaroxaban
  • Dabigatran


Answer: Warfarin


43. A patient on dabigatran needs emergency surgery. The administration of idarucizumab would be expected to:

  • Slowly reverse the anticoagulant effect over 24 hours
  • Rapidly reverse the anticoagulant effect of dabigatran
  • Increase the anticoagulant effect
  • Have no effect on dabigatran’s activity


Answer: Rapidly reverse the anticoagulant effect of dabigatran


44. Extended treatment of VTE (beyond 3-6 months) with a DOAC is done to:

  • Cure the patient of their hypercoagulable state
  • Prevent the recurrence of VTE
  • Monitor for long-term side effects
  • Ensure the patient remains on a high-cost medication


Answer: Prevent the recurrence of VTE


45. Which DOAC is a prodrug that is converted to its active form after absorption?

  • Apixaban
  • Rivaroxaban
  • Dabigatran etexilate
  • Edoxaban


Answer: Dabigatran etexilate


46. The primary safety concern with all anticoagulants, including DOACs, is the risk of:

  • Hyperglycemia
  • Hypertension
  • Bleeding
  • Thrombosis


Answer: Bleeding


47. A pharmacist educating a patient on rivaroxaban for VTE treatment should emphasize taking the 15 mg and 20 mg tablets:

  • On an empty stomach
  • With a full meal
  • Only at bedtime
  • With a large glass of grapefruit juice


Answer: With a full meal


48. In the peri-procedural setting, restarting a DOAC after a surgery with a high risk of bleeding should be:

  • Done immediately after the procedure ends
  • Delayed for 24-72 hours, depending on the procedure and bleeding risk
  • Done with a large loading dose
  • Switched to warfarin for one week


Answer: Delayed for 24-72 hours, depending on the procedure and bleeding risk


49. An understanding of DOAC literature is important for a pharmacist to:

  • Critically evaluate new clinical trials and apply them to patient care
  • Memorize the price of each DOAC
  • Learn how to compound DOACs from powder
  • Market DOACs to physicians


Answer: Critically evaluate new clinical trials and apply them to patient care


50. The development of DOACs represents a major advance in anticoagulation therapy by providing options that are:

  • More effective and safer for all patients in every situation
  • Less expensive than warfarin
  • Often more convenient and safer in certain aspects compared to warfarin
  • Free from any risk of bleeding


Answer: Often more convenient and safer in certain aspects compared to warfarin

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